In today's power management systems combinations of a switching converter, like a DC/DC converter, with a cascaded linear regulator are common. The DC/DC converter is primarily used to provide a sufficient power conversion to a higher or lower voltage with respect to a supplied voltage. The linear regulator, for example a low drop-out regulator, LDO, is cascaded in series to this switching converter to provide a voltage with accurate output having lower ripple. The output voltage provided by the combination is provided accurately with almost zero ripple.
In known implementations of such cascaded power management systems the switching converter's output voltage is fixed. The linear regulator is designed such that a minimum drop-out voltage across this linear regulator is realized for a predefined peak load current. This results in power inefficiency for all load conditions other than the peak load.
Other known implementations use the output voltage of the linear regulator to generate a feedback signal in a control circuitry to adjust the switching converter. This also results in power inefficiency.
It is therefore an objective to provide a power conversion arrangement and method with enhanced efficiency.
The objective is achieved by the subject-matter of the independent patent claims. Embodiments and developments are subject-matter of the dependent claims.